Bring about the Apocalypse, or watch everyone I've ever cared about die. Easy right?

I didn't want to be a pawn in the schemes of a childish God, but I was left little choice. With the souls of my family at stake, I agreed to take part in the mad God's game.

I became the Demon Lord, the harbinger of the apocalypse; Sent out to destroy the world by any means necessary. But I'm the villain of this story, and there must be a hero to oppose me. On the side of white is the Archangel, who is hell-bent on defeating me. I'll need to gather my pieces and form an army to oppose her and bring about the end of the world.

All isn't hopeless, though. If I win, I'll be granted a wish. I can undo everything and save the world; But first I have to destroy it.